In temperature sensor 1 illustrated in FIG. 6, temperature-sensitive element 3 is disposed inside bottomed cylindrical case 2 and is sealed with coupler 4. Bolt part 7 that includes screw part 5 and bolt head part 6 and is used when temperature sensor 1 is externally installed is provided in case 2. In other words, when a material of case 2 is metal, bolt part 7 is also formed of the same metal, and when the material of case 2 is resin, bolt part 7 is also formed of the same resin.
Here, when a target of temperature detection is liquid such as an engine oil, shielding performance of the liquid must be secured. Therefore, a metallic material such as a copper material or a steel material is used as the material of case 2.
For example, PTL 1 and PTL 2 are known as prior art document information associated with the present invention.